KR20010102208A - Antenna Duplexer - Google Patents

Abstract

In the transmission-side characteristics of the antenna common apparatus, the insertion loss and the VSWR characteristics near the center frequency of the pass band are improved. The phase substrate 13 is electrically connected to the output side of the SAW filter 11 for transmission. The receiving SAW filter 12 is electrically connected to the phase substrate 13. Here, the transmission filter 11 and the reception filter 12 each have a passband different in frequency, and attenuate the passbands on the other side. The phase substrate 13 rotates the phase of the transmission band of the reception SAW filter 12, and the magnitude of the reflection coefficient of the reception filter 12 at the center frequency of the transmission band is 0.8 or more and the phase of the reflection coefficient. It has a phase angle and characteristic impedance where the angle is 0 to 45 °.

Description

Antenna Duplexer {Antenna Duplexer}

In a conventional antenna common device, a transmitting surface acoustic wave filter and a receiving surface acoustic wave filter are connected inside a package through a phase circuit.

This phase circuit has a function of rotating the phase of the transmission band of the receiving surface acoustic wave filter, and the reflection coefficient at the center frequency of the transmission band of the receiving surface acoustic wave filter is 0.8 or more and the reflection coefficient is phased. The angle is about 0 ° and the characteristic impedance is about 50Ω.

The impedance in the passband of the surface acoustic wave filter is generally lower than 50 Ω and is capacitive. Therefore, in the above configuration, it is difficult to achieve 50Ω matching in both the transmission band and the reception band, and the insertion loss and voltage standing wave ratio (hereinafter referred to as VSWR) in the pass band are large.

The present invention relates to an antenna common device used in a mobile communication device.

1 is a perspective view of an antenna common apparatus according to an embodiment of the present invention.

2 shows a circuit of an antenna common according to an embodiment of the present invention.

Fig. 3 shows the relationship between the impedance of the phase substrate and the insertion loss of the antenna common unit in the vicinity of the center frequency of the pass band of the receiving surface acoustic wave filter according to the embodiment of the present invention.

Fig. 4 shows the relationship between the impedance of the phase substrate and the VSWR of the antenna common unit in the vicinity of the center frequency of the pass band of the receiving surface acoustic wave filter according to the embodiment of the present invention.

Fig. 5 shows the relationship between the phase angle of the phase substrate and the insertion loss of the antenna common unit in the vicinity of the center frequency of the pass band of the surface acoustic wave filter for transmission according to the embodiment of the present invention.

Fig. 6 shows the relationship between the phase angle of the phase substrate and the VSWR of the antenna common unit in the vicinity of the center frequency of the pass band of the surface acoustic wave filter for transmission according to the embodiment of the present invention.

7 shows a circuit of a phaser in another embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

11 surface acoustic wave filter for transmission 12 surface acoustic wave filter for reception

13: phase substrate 14: package

15: antenna terminal 16: transmitting terminal

17: Receive terminal 18a: Connection putt

18b: Connection putt 18c: Connection putt

19a: Ground Terminal 19b: Ground Terminal

19c: Grounding terminal 19d: Grounding terminal

19e: Grounding terminal 20a: Bonding wire

20b: bonding wire 20c: bonding wire

20d: Bonding Wire 20e: Bonding Wire

30: input terminal 31: output terminal

32: inductance element 33: coupling capacitance

34: capacitance element 35: capacitance element

SUMMARY OF THE INVENTION An object of the present invention is to provide an antenna common with excellent insertion loss and VSWR characteristics in a pass band in which impedance matching at an antenna terminal of a transmission band and a reception band is optimized.

In view of the conventional problems, the antenna common apparatus of the present invention comprises: a phase shifter electrically connected to one end of the surface acoustic wave filter for transmission and ii) an output side of the surface acoustic wave filter for transmission; It has a receiving surface acoustic wave filter electrically connected to the input side.

The surface acoustic wave filters for transmission and reception have passbands of different frequencies, respectively, and attenuate passbands on the other side.

The phase shifter has a function of rotating the phase in the transmission band of the receiving surface acoustic wave filter, and the magnitude of the reflection coefficient at the center frequency of the transmission band of the receiving surface acoustic wave filter is 0.8 or more, and the phase angle of the reflection coefficient. Is 0 to 45 °.

Therefore, the inductive component is added in parallel to the antenna end side in the passband of the impedance and the capacitive surface acoustic wave filter for transmission which is lower than 50?. Therefore, the impedance of the transmission band at the antenna terminal of the antenna common device can be closer to 50 Ω matching.

Thus, the antenna common device of the present invention is excellent in insertion loss and VSWR characteristics in its passband.

Embodiments of the present invention provide a surface acoustic wave filter for transmission, a phase with one end electrically connected to the output side of the surface acoustic wave filter for transmission, and a receiving surface acoustic wave filter with the input side electrically connected to the other end of the phase retarder. It is composed with.

The transmitting surface acoustic wave filter and the receiving surface acoustic wave filter each have a passband having a different frequency and attenuate different passbands, and the phase shifter rotates at least a phase in the transmission band of the receiving surface acoustic wave filter. Has

The phase shifter rotates the phase of the transmission band of the receiving surface acoustic wave filter so that the magnitude of the reflection coefficient at the center frequency of the transmission band of the reception surface acoustic wave filter is 0.8 or more, and the phase angle of the reflection coefficient is 0 to 45. It has a phase angle and a characteristic impedance in degrees.

Accordingly, the antenna sharing device has 50 Ω matching in the transmission band at the antenna terminal than the conventional antenna sharing device, and the insertion loss at the transmitting side of the antenna sharing device is small, and the VSWR characteristic is excellent.

Another embodiment of the present invention is the antenna common of the above-described embodiment, wherein the characteristic impedance of the phaser is lower than 50Ω match.

Since the impedance in the pass band of the receiving surface acoustic wave filter is lower than 50 Ω, 50 Ω matching is obtained in the reception band at the antenna terminal by using the phase shifter.

Therefore, the antenna common machine has excellent VSWR characteristics at the transmitting side and the receiving side, and the insertion loss is reduced.

Another embodiment of the present invention is, in addition to the embodiment just described, an antenna common whose characteristic impedance of the phaser is 42 ± 8 Ω (except 50 Ω). This antenna common has excellent VSWR characteristics at the transmitting side and the receiving side and has a low insertion loss.

Another embodiment of the present invention, in addition to the embodiment described earlier, the transmission surface acoustic wave filter is composed of a ladder-type filter, the anti-resonance of the parallel surface acoustic wave (SAW) resonator It is an antenna common device whose resonant frequency is higher than that of the series complete SAW resonator.

This antenna sharer can obtain a wide band filter characteristic without degrading the VSWR characteristic and insertion loss at the transmitting side.

Another embodiment of the present invention is an antenna common apparatus in which the phase angle of the phaser is 90 ± 10 ° in addition to the embodiment described first. This antenna common is matched by 50 Ω in the transmission band at the antenna terminal. This antenna common has excellent VSWR characteristics on its transmission side and reduces insertion loss.

In another embodiment of the present invention, in addition to the embodiment described earlier, an antenna common device having a phase impedance of 42 ± 8 Ω (except 50 Ω) and a phase angle of 90 ± 10 °, The impedance in the reception band in 50 ohms is matched. Therefore, this antenna sharer has excellent VSWR characteristics and a low insertion loss not only at the transmitting side but also at the receiving side.

The antenna common unit according to another embodiment of the present invention electrically connects one end side to the output side of the transmission SAW filter and the transmission SAW filter and the input side to the other end side of the phaser in the same manner as the above-described embodiment. It has a receiving SAW filter.

Here, the transmission SAW filter and the reception SAW filter each have a passband different in frequency, and attenuate passbands on the other side.

The phaser has a function of rotating the phase in the transmission band of the receiving SAW filter and its characteristic impedance is lower than 50?.

Therefore, 50? Matching of the impedance of the reception band at the antenna terminal of this antenna common device is obtained. Thus, this antenna common has excellent VSWR characteristics at the receiving side, and insertion loss is also reduced.

Another embodiment of the present invention is, in addition to the embodiment just described, an antenna common whose characteristic impedance of the phaser is 42 ± 8 Ω (except 50 Ω). The impedance in the reception band at the antenna terminal of this antenna common unit is matched to 50 Ω. Therefore, this antenna common has excellent VSWR characteristics at the receiving side, and insertion loss is also reduced.

First embodiment

1 is a perspective view of an antenna common apparatus according to Embodiment 1 of the present invention.

In this antenna common unit, a transmission SAW filter 11, a reception SAW filter 12, and a phase substrate 13 formed by a bladder electrode or the like are formed on a piezoelectric substrate. These are housed inside the package 14. An antenna terminal 15, a transmitting terminal 16, a receiving terminal 17, a ground terminal 19a to 19e are disposed at an outer circumferential portion of the package 14, and connection pads 18a to 18c are disposed inside the package 14. do. The connecting putt 18a is connected to the antenna terminal 15, the connecting putt 18b is connected to the transmitting terminal 16, and the connecting putt 18c is connected to the receiving terminal 17, respectively.

In addition, the transmission SAW filter 11, the reception SAW filter 12, and the phase substrate 13 each have two connection terminals. One terminal of the transmission SAW filter 11 and the connection putt 18b are connected to the bonding wire 20a, and the other terminal and the connection putt 18a are connected to the bonding wire 20b.

Similarly, one terminal of the receiving SAW filter 12 and the connection putt 18c are the bonding wires 20e, and the other terminal and the one terminal of the phase substrate 13 are the bonding wires 20d and the phase substrate. The other terminal of (13) and the connection putt 18a are respectively connected by the bonding wire 20c.

FIG. 2 is a circuit of an antenna sharer, in which the same components as shown in FIG. 1 are given the same reference numerals.

The phase substrate 13 has a function of rotating at least the phase of the transmission band of the reception SAW filter 12. The characteristic impedance is lower than 50 Ω and is 42 ± 8 Ω (except 50 Ω).

As shown in Figs. 3 and 4, it can be seen that the insertion loss and the VSWR of the reception characteristic of the antenna common unit are reduced as the characteristic impedance of the phase substrate 13 is smaller than 50?. However, if the characteristic impedance becomes too low, the insertion loss and the VSWR of the transmission characteristic of the antenna common equipment deteriorate. Therefore, it is preferable that the characteristic impedance of the phase substrate 13 is 42 ± 8 Ω (except 50 Ω).

Second embodiment

The antenna shared device of the second embodiment of the present invention has the same configuration as the antenna shared device of the first embodiment, and will be described with reference to FIGS. 1 and 2. The difference from Example 1 is described about the characteristic of the antenna common apparatus of Example 2. FIG.

The transmission SAW filter 11 is composed of a leather-type filter and makes the resonance frequency of the series SAW resonator higher than the anti-resonance frequency of the parallel SAW (elastic surface wave) resonator.

The phase substrate 13 has a function of rotating the phase of the transmission band of the reception SAW filter 12 in the transmission band, and the magnitude of the reflection coefficient of the reception SAW filter 12 at the center frequency of the transmission band is It has a phase angle and characteristic impedance of 0.8 or more and a phase angle of reflection coefficient of 0 to 45 °.

Specifically, the phase angle of the phase substrate 13 is set to 90 ± 10 ° and the characteristic impedance to 42 ± 8 Ω (excluding 50 Ω) lower than 50 Ω.

According to the above structure, as in the first embodiment, as shown in FIGS. 3 and 4, the characteristic impedance of the phase substrate 13 is made smaller than 50?, So that the antenna common apparatus in the vicinity of the center frequency of the receiving SAW filter 12 Insertion loss and VSWR become small.

However, if the characteristic impedance becomes too low, the insertion loss and the VSWR in the transmission characteristics of the antenna common equipment deteriorate.

Therefore, the characteristic impedance of the phase substrate 13 is preferably 42 ± 8 Ω (except 50 Ω). By using the phase substrate 13 having a phase angle of 80 to 100 °, the magnitude of the reflection coefficient at the center frequency of the transmission band of the receiving SAW filter 12 can be 0.8 or more and the phase angle can be 0 to 45 °. have.

As a result, as shown in Figs. 5 and 6, the insertion loss and the VSWR can be simultaneously reduced in the transmission characteristics of the antenna common apparatus.

As described above, the insertion loss and the VSWR can be reduced in the reception characteristics and the transmission characteristics of the antenna common apparatus.

In addition, in each of the above embodiments, the case where the transmission SAW filter 11, the reception SAW filter 12 and the phase substrate 13 are housed in one package 14 has been described.

In addition, when using a package incorporating a phase circuit, it is not necessary to use the phase substrate 13 and the size can be reduced.

In addition, the transmission SAW filter 11, the reception SAW filter 12, and the phase substrate 13 may not be housed in one package.

Furthermore, instead of the phase substrate 13, you may comprise a phase machine from discrete components. In that case, it is preferable to use the structure as shown in FIG.

In Fig. 7, the inductance element 32 and the coupling capacitor 33 are connected in parallel in series between the input terminal 30 and the output terminal 31 of the phase shifter. Furthermore, capacitance elements 34 and 35 having one end grounded between the input terminal 30 and a parallel circuit composed of the element 32 and the capacitor 33 and between the parallel circuit and the output terminal 31 are connected. do.

As described above, according to the present invention, in each pass band of the transmission SAW filter and the reception SAW filter of the antenna common device, the insertion loss and the VSWR at each center frequency and its vicinity can be reduced.

Claims (8)

As an antenna common unit, SAW filter for transmission, A phase shifter having one end electrically connected to an output side of the transmission SAW filter, A receiving SAW filter electrically connected to the input side of the other phase of the phase shifter, The transmission SAW filter and the reception SAW filter each have a passband having a different frequency, and attenuate passbands of different sides. The phase shifter i) rotates the phase of the transmission band of the reception SAW filter, and ii) the magnitude of the reflection coefficient at the center frequency of the transmission band of the reception SAW filter is 0.8 or more, and the reflection coefficient Antenna common equipment with phase angle and characteristic impedance of which phase angle is from 0 to 45 °. The antenna common device according to claim 1, wherein a characteristic impedance of the phase shifter is lower than 50 Ω. 3. The antenna common device according to claim 2, wherein the characteristic impedance of the phaser is 42 ± 8Ω except 50Ω. 2. The antenna common device according to claim 1, wherein the transmission SAW filter is composed of a ladder filter, and the resonance frequency of the series-type SAW resonator is higher than the anti-resonant frequency of the parallel-type SAW resonator. The antenna common device according to claim 1, wherein the phase angle of the phaser is 90 ± 10 °. The antenna common device according to claim 1, wherein the characteristic impedance of the phaser is 42 ± 8Ω except 50Ω, and the phase angle is 90 ± 10 °. As an antenna common unit, SAW filter for transmission A phase device having one end electrically connected to an output side of the transmission SAW filter; A receiving SAW filter electrically connected to the input side of the other phase of the phase shifter, The transmitting SAW filter and the receiving SAW filter each have a passband having a different frequency, and attenuate passbands on the other side, And the phase shifter rotates the phase of the transmission band of the reception SAW filter and has a characteristic impedance of less than 50?. 8. The antenna common device according to claim 7, wherein the characteristic impedance of the phaser is 42 ± 8Ω except for 50Ω.